To portage a canoe, the canoe is inverted and then placed on the shoulders and neck of a canoeist. The weight of the canoe is usually transmitted to the shoulders and neck through a center thwart or other centrally located cross member.
A portaging thwart may be designed to distribute the weight of a canoe over the shoulders and neck of a canoeist in such a way as to lessen discomfort. The weight can be more evenly distributed by padding the portaging thwart or by forming the portaging thwart with a recessed portion so that it conforms somewhat with the shape of the shoulders and neck of the canoeist. However, as the conventional portaging thwart is rigidly attached to the gunwales of the canoe, the angle of the portaging thwart relative to the shoulders and neck of the canoeist cannot be adjusted to suit the individual anatomy of the canoeist.
Furthermore, the orientation of the portaging thwart on the shoulders and neck of the canoeist changes when the canoe is rotated relative to the canoeist. Such undesirable rotation occurs, for example, when the canoeist ascends or descends an incline: the body of the canoeist remains generally vertical so that the canoeist can maintain his or her balance, while the canoe is angled upwardly (during an ascent) or downwardly (during a descent) to avoid contacting the ground. The portaging thwart moves with the canoe and, as a result, the weight of the canoe may be transmitted to the shoulders and neck of the canoeist in an uncomfortable fashion, such as through pressure points.
The prior art has not solved the problem of the discomfort caused to the shoulders and neck of a canoeist due to the rotation of the portaging thwart relative to the shoulders and neck during the ascent or descent of inclines, nor does it reveal a portaging thwart the angle of which is adjustable to suit the individual anatomy of the canoeist. For instance, Canadian Patent No. 490,888 (Massicotte) teaches a canoe with a center thwart which contains two indentations, one facing the bow of the canoe and one facing the stern thereof. The indentations are designed to increase comfort during a portage by fitting around the back of the neck of a canoeist. As the indentations are on opposite sides of the thwart, the canoeist may face either the bow or the stern of the canoe.
Canadian Patent No. 948,491 (Erickson) teaches a canoe with a fixed center thwart formed to have a neck opening and a shoulder recess to increase comfort during portaging.
Canadian Patent No. 1,197,733 (Poitras) teaches a canoe with a center thwart which includes a neck recess and two adjustable shoulder supports. The shoulder supports are designed to transfer the weight of the canoe to the shoulders and neck of a canoeist in a relatively comfortable fashion.
United States Pat. No. 4,357,894 (Kirk) teaches a canoe with two thwarts oriented longitudinally rather than in the conventional transverse arrangement. The position of the thwarts on the gunwales is adjustable so that optimum weight distribution can be achieved. However, the thwarts are not suitable for portaging.
United States Pat. No. 4,873,935 (Lustig) teaches a canoe to which is rigidly attached a portaging thwart which is longitudinally oriented. The thwart contains no neck recess but is divided in two so as to accommodate the head of a canoeist.
None of the above patents offers a solution to the problem of the discomfort caused to the shoulders and neck of a canoeist due to the rotation of the portaging thwart relative to the shoulders and neck during the ascent or descent of inclines, nor does it reveal a portaging thwart the angle of which is adjustable to suit the individual anatomy of the canoeist. I have found, however, that these problems can be overcome by providing a portaging thwart capable of axial rotation relative a canoe. The result is that, relative to the canoeist, the portaging thwart remains stationary while the canoe rotates.